Students of the Park Slope Rock School wait before performing on stage at La Bellevilloise concert hall in Paris. [Photo/Agencies]

Can't believe their ears

But all had seen how their children started playing from the very first day at Park Slope Rock School, founded in Brooklyn by American musician Jason Domnarski in 2008 before he opened a branch in the French capital three years later.

At first Langlois could not believe her eyes, nor her ears.

"The kids came home playing straight away, " she says. "It is not at all how music teaching used to be. So I thought, 'Why should they have all the fun?'"

Laura Malone, on flute and lead guitar, had the same reaction. "After I saw my daughter play in her band and saw the way Jason worked with the kids, the first thing I thought was 'Why didn't this exist when I was young?'"

And so five parents on the wrong side of 40 came knocking on Domnarski's door asking if he could do for them what he had done for their kids.

"I thought why not," Domnarski says, though he admits that he doubted if they would adapt to his mould-breaking approach as well as their children.

"I thought they might be more worried about making mistakes, but they have been amazing from the get-go and so supportive of each other."

Malone－a computer programmer who had never played guitar before－says the "dynamics of being in the band helps get you over hurdles" that you might baulk at alone. "The band has built this amazing bond just from practising together for an hour and a half a week. I would never had believed it had I not seen it myself."